Noninvasive devices, methods, and systems for shrinking of tissues

ABSTRACT

The invention provides improved devices, methods, and systems for shrinking of collagenated tissues, particularly for treating urinary incontinence in a noninvasive manner by directing energy to a patient&#39;s own support tissues. This energy gently heats fascia and other collagenated support tissues, causing them to contract. The energy will preferably be applied between a pair of large plate electrodes having cooled flat electrode surfaces. Such cooled plate electrodes are capable of directing electrical energy through an intermediate tissue and into fascia while the cooled electrode surface prevents injury to the intermediate tissue. Ideally, the plate electrode comprises an electrode array including discrete electrode surface segments so that the current flux can be varied to selectively target the fascia.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. patent applications Ser. No.08/910,370, (Attorney Docket No. 17761-000120), Ser. No. 08/910,775,(Attorney Docket No. 17761-000300), and Ser. No. 08/910,371, (AttorneyDocket No. 17761-000320), all filed concurrently herewith, the fulldisclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to medical devices, methods, andsystems. More specifically, the present invention provides techniquesfor selectively heating and shrinking tissues, particularly for thenoninvasive treatment of urinary incontinence and hernias, for cosmeticsurgery, and the like.

Urinary incontinence arises in both women and men with varying degreesof severity, and from different causes. In men, the condition occursalmost exclusively as a result of prostatectomies which result inmechanical damage to the sphincter. In women, the condition typicallyarises after pregnancy where musculoskeletal damage has occurred as aresult of inelastic stretching of the structures which support thegenitourinary tract. Specifically, pregnancy can result in inelasticstretching of the pelvic floor, the external sphincter, and most often,to the tissue structures which support the bladder and bladder neckregion. In each of these cases, urinary leakage typically occurs when apatient's intra-abdominal pressure increases as a result of stress, e.g.coughing, sneezing, laughing, exercise, or the like.

Treatment of urinary incontinence can take a variety of forms. Mostsimply, the patient can wear absorptive devices or clothing, which isoften sufficient for minor leakage events. Alternatively oradditionally, patients may undertake exercises intended to strengthenthe muscles in the pelvic region, or may attempt behavior modificationintended to reduce the incidence of urinary leakage.

In cases where such noninterventional approaches are inadequate orunacceptable, the patient may undergo surgery to correct the problem. Avariety of procedures have been developed to correct urinaryincontinence in women. Several of these procedures are specificallyintended to support the bladder neck region. For example, sutures,straps, or other artificial structures are often looped around thebladder neck and affixed to the pelvis, the endopelvic fascia, theligaments which support the bladder, or the like. Other proceduresinvolve surgical injections of bulking agents, inflatable balloons, orother elements to mechanically support the bladder neck.

Each of these procedures has associated shortcomings. Surgicaloperations which involve suturing of the tissue structures supportingthe urethra or bladder neck region require great skill and care toachieve the proper level of artificial support. In other words, it isnecessary to occlude or support the tissues sufficiently to inhibiturinary leakage, but not so much that intentional voiding is madedifficult or impossible. Balloons and other bulking agents which havebeen inserted can migrate or be absorbed by the body. The presence ofsuch inserts can also be a source of urinary tract infections.Therefore, it would be desirable to provide an improved therapy forurinary incontinence.

A variety of other problems can arise when the support tissues of thebody have excessive length. Excessive length of the pelvic supporttissues (particularly the ligaments and fascia of the pelvic area) canlead to a variety of ailments including, for example, cystocele, inwhich a portion of the bladder protrudes into the vagina. Many herniasare the result of a strained, torn, and/or distended containing tissue,which allows some other tissue or organ to protrude beyond its containedposition. Cosmetic surgeries are also often performed to decrease thelength of support tissues. For example, abdominoplasty (often called a"tummy tuck") is often performed to decrease the circumference of theabdominal wall. The distortion of these support tissues may be due tostrain, advanced age, congenital predisposition, or the like.

Unfortunately, many support tissues are difficult to access, and theirtough, fibrous nature can complicate their repair. As a result, thetherapies now used to improve or enhance the support provided by theligaments and fascia of the body often involve quite invasive surgicalprocedures.

For these reasons, it would be desirable to provide improved devices,methods, and systems for treating fascia, tendons, and the other supporttissues of the body. It would be particularly desirable to provideimproved noninvasive or minimally invasive therapies for these supporttissues, especially for the treatment of urinary incontinence in men andwomen. It would further be desirable to provide treatment methods whichmade use of the existing support structures of the body, rather thandepending on the specific length of an artificial support structure.

2. Description of the Background Art

U.S. Pat. No. 5,423,811 describes a method for RF ablation using acooled electrode. U.S. Pat. Nos. 5,458,596 and 5,569,242 describemethods and an apparatus for controlled contraction of soft tissue. AnRF apparatus for controlled depth ablation of soft tissue is describedin U.S. Pat. No. 5,514,130.

U.S. Pat. No. 4,679,561 describes an implantable apparatus for localizedheating of tissue, while U.S. Pat. No. 4,765,331 describes anelectrosurgical device with a treatment arc of less than 360 degrees. Animpedance and temperature generator control is described in U.S. Pat.No. 5,496,312. Bipolar surgical devices are described in U.S. Pat. Nos.5,282,799, 5,201,732, and 728,883.

SUMMARY OF THE INVENTION

The present invention provides devices, methods, and systems forshrinking of collagenated tissues, particularly for treating urinaryincontinence in a noninvasive manner. In contrast to prior arttechniques, the present invention does not rely on implantation ofballoons or other materials, nor does it rely on suturing, cutting, orother direct surgical modifications to the natural support tissues ofthe body. Instead, the present invention directs energy to a patient'sown support tissues. This energy gently heats fascia and othercollagenated support tissues, causing them to contract withoutsubstantial necrosis of adjacent tissues. The energy will preferably beapplied through a large, cooled electrode having a substantially flatelectrode surface. Such a cooled plate electrode is capable of directingelectrical energy through an intermediate tissue and into fascia, whilethe cooled electrode surface prevents injury to the intermediate tissue.Ideally, the plate electrode comprises an electrode array which includesseveral discrete electrode surface segments so that the current flux canbe varied to selectively target and evenly heat the fascia. In someembodiments, the tissue is heated between a pair of parallel cooledelectrode surfaces, the parallel surfaces optionally being planar,cylindrical, spherical, or the like.

In a first aspect, the present invention provides a system fortherapeutically heating a target zone within a tissue. The systemcomprises a first electrode having a first electrode surface which isengagable against the tissue. A second electrode has a second electrodesurface which can be aligned substantially parallel to the firstelectrode surface, with the tissue positioned therebetween. Anelectrical current flux between these parallel electrodes cansubstantially evenly heat the target zone. A cooling system is coupledto at least one of the electrodes for cooling the electrode surface.Generally, radiofrequency current is used to avoid tissue stimulation.

In another aspect, the present invention provides a method fortherapeutically heating a target zone of a patient body. The target zoneis disposed within a tissue between first and second tissue surfaces.The method comprises engaging a first electrode surface against thefirst tissue surface. A second electrode surface is alignedsubstantially parallel with the first electrode surface and against thesecond tissue surface. An electrical potential is applied between thefirst and second electrodes so as to produce an electrical current fluxwhich heats the target zone. At least one of the first and second tissuesurfaces is cooled by the engaged electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a system for heating and shrinkingfascia disposed between adjacent tissue layers by heating the fasciabetween a pair of large, cooled, flat electrode arrays, according to theprinciples of the present invention.

FIG. 2 schematically illustrates the even heating provided by a currentflux between the large, cooled, flat electrode surfaces of the system ofFIG. 1.

FIGS. 2A-2F schematically illustrate methods for selectively energizingthe electrode surface segments of the large, flat electrode arrays ofthe system of FIG. 1 to tailor the current flux throughout a targetzone.

FIGS. 3-3E graphically illustrate a method for heating a target tissuebetween cooled electrodes, wherein the electrode surfaces cool thetissue before, during, and after radiofrequency energy is applied.

FIG. 4 is a cut-away view illustrating pelvic support structures whichcan be targeted for non-invasive selective contraction using the methodsof the present invention.

FIGS. 4A-4C illustrate contraction and reinforcing of the pelvic supporttissues of FIG. 4 as a therapies for female urinary incontinence.

FIG. 5 is a perspective view of a system for treating female urinaryincontinence by selectively shrinking the endopelvic fascia, accordingto the principles of the present invention.

FIG. 6 is a cross-sectional view illustrating a method for using thesystem of FIG. 5 to treat female urinary incontinence.

FIG. 7 illustrates an alternative bladder electrode structure for use inthe method of FIG. 6.

FIGS. 8A and 8B illustrate an alternative vaginal probe having a balloondeployable electrode for use in the method of FIG. 6.

FIG. 9 is a cross-sectional view illustrating a structure and a methodfor ultrasonically positioning a temperature sensor within a targettissue.

FIG. 10 illustrates an alternative system for selectively shrinkingfascia through intermediate tissues, according to the principles of thepresent invention.

FIG. 11 schematically illustrates an alternative method for selectivelyshrinking endopelvic fascia using a vaginal probe having a cooledelectrode array.

FIG. 12 schematically illustrates a method for selectively shrinkingendopelvic fascia by applying a bipolar potential between electrodesegments of a vaginal probe, and by electrically insulating a surface ofthe endopelvic fascia opposite the probe.

FIG. 13 schematically illustrates a method for selectively shrinkingendopelvic fascia by transmitting microwave or ultrasound energy from acooled vaginal probe.

FIG. 14 is a cross-sectional view illustrating a method for selectivelyshrinking endopelvic fascia by grasping and folding the endopelvicfascia to facilitate focusing of heating upon the fascia, and to enhanceshrinkage of the fascia by decreasing tension in the fascia while thefascia is heated, according to the principles of the present invention.

FIG. 15 is a schematic illustration of a kit including the vaginal probeof FIG. 5, together with instructions for its use to shrink tissues,according to the methods of the present invention.

DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENTS

The present invention optionally relies on inducing controlled shrinkageor contraction of a support tissue of the body, typically being acollagenated tissue such as fascia, ligament, or the like. For treatmentof urinary incontinence, the tissue structure will be one that isresponsible in some manner for control of urination, or for supporting asuch a tissue. Exemplary tissue structures include the urethral wall,the bladder neck, the bladder, the urethra, bladder suspensionligaments, the sphincter, pelvic ligaments, pelvic floor muscles,fascia, and the like. Treatment of other conditions may be effected byselective shrinking of a wide variety of other tissues, including (butnot limited to) the diaphragm, the abdominal wall, the fascia andligaments of the joints, and the like. Related devices, methods, andsystem are also described in co-pending U.S. patent application Ser. No.08/910,370, (Attorney Docket No. 017761-000120) filed herewith, the fulldisclosure of which is incorporated herein by reference.

Tissue contraction results from controlled heating of the tissue byaffecting the collagen molecules of the tissue. Contraction occurs as aresult of heat-induced uncoiling and repositioning of the collagenβ-pleated structure. By maintaining the times and temperatures set forthbelow, significant tissue contraction can be achieved withoutsubstantial collateral tissue necrosis.

The temperature of the target tissue structure will generally be raisedto a value in the range from about 60° C. to 110° C., often being in therange from about 60° C. to 80° C., and will generally effect a shrinkageof the target tissue in at least one dimension of between about 20 and50 percent. In many embodiments, heating energy will be applied for aperiod of from 30 seconds to 5 minutes. These heating times will varywith separation between the parallel plate electrodes, with a heat timeof about 5 minutes often being appropriate for an electrode separationof about 4 cm. Shorter heat times may be used with smaller electrodeseparation distances.

The rise in temperature may be quite fast, although there will often beadvantages in heating tissues more slowly, as this will allow more heatto be removed from tissues which are not targeted for therapy, therebyminimizing collateral damage. However, if too little heating energy isabsorbed by the tissue, blood perfusion will transfer the heat away fromthe targeted tissue, so that the temperature will not rise sufficientlyto effect therapy. Fortunately, fascia and other support tissues oftenhave less bloodflow than adjacent tissues and organs; this may helpenhance the heating of fascia and minimize necrosis of the surroundingstructures.

The total amount of energy delivered will depend in part on which tissuestructure is being treated, how much tissue is disposed between thetarget tissue and the heating element, and the specific temperature andtime selected for the protocol. The power delivered will often be in therange from 10 W to 100 W, usually being about 20 W. The temperature willusually not drop instantaneously when the heating energy stops, so thatthe tissue may remain at or near the therapy temperature for a time fromabout 10 seconds to about 2 minutes, and will often cool gradually backto body temperature.

While the remaining description is generally directed at devices andmethods for treatment of urinary stress incontinence of a femalepatient, it will be appreciated that the present invention will findmany other applications for selectively directing therapeutic heatingenergy into the tissues of a patient body for shrinking of tissues, forablation of tissues and tumors, and the like.

FIG. 1 schematically illustrates a system 10 for shrinking a fascia Fdisposed between first and second adjacent tissues T1, T2. System 10includes a pair of electrodes 12, 14 having large, substantially planartissue engaging surfaces. Electrodes 12, 14 are aligned substantiallyparallel to each other with the fascia (and adjacent tissues) disposedtherebetween.

The surfaces of electrodes 12, 14 which engage the tissue are cooled bya cooling system 16. The cooling system will typically include a conduitthrough the electrode for the circulation of a cooling fluid, but mayoptionally rely on thermoelectric cooling or the like. The temperatureof the electrode surface may be regulated by varying the temperature orflow rate of the cooling fluid. Cooling may be provided through the useof an ice bath, by endothermic chemical reactions, by standard surgicalroom refrigeration mechanisms, or the like. Ideally, the cooling systemcools an area which extends beyond the energized electrode surfaces toprevent any hot spots adjacent the tissue surface, and to maximize theheat removal from the tissue without having to resort to freezing thetissue.

Each of the electrodes is separated into a plurality of electrodesegments. For example, the electrode includes electrode segments 12a,12b, 12c, 12d, and 12e, each of which is electrically isolated from theothers. This allows the electrode segments to be individually energized.Electrodes 12, 14 are energized by a radiofrequency (RF) power source18. Multiplexers 20 individually energize each electrode segment,typically varying the power or time each segment is energized to morenearly uniformly heat fascia F. A controller 22 will typically include acomputer program which directs the application of cooling flow and RFpower through electrodes 12, 14, ideally based at least in part on atemperature signal sensed by a temperature sensor 24. Temperature sensor24 may sense the temperature of the tissue at the tissue/electrodeinterface, or may alternatively sense the temperature of the fasciaitself.

The use of large cooled plate electrodes to direct an even electricalcurrent flux can be understood with reference to the simplifiedcross-sectional illustration of FIG. 2. In this example, RF power isapplied uniformly across parallel plate electrodes 12, 14 to produce acurrent through tissue T. As the electrode surfaces are substantiallyplanar, and as the electrode surfaces are large compared to theseparation between the electrodes, a current flux 26 is substantiallyuniform throughout that portion of the tissue which is disposed betweenthe electrode surfaces. The flow of electrical current through theelectrical resistance of the tissue causes the temperature of the tissuethrough which the current passes to rise. The use of relatively lowradiofrequency current, preferably in the range from 100 kHz to 1 MHz,helps to avoid collateral damage to nerve and muscle tissues.

Preliminary work in connection with the present invention has shown thatfascia and other collagenated tissues which are heated to a temperaturerange of between about 60° C. and 110° C., and preferably between about60° C. and 80° C., will contract. In fact, unstressed fascia will shrinkbetween about 30% and 50% when heated for a very short time, preferablyfrom between about 0.5 seconds to 5 seconds. Such heating can easily beprovided by conduction of RF currents through the tissue.

The uniform current flux provided by the large plate electrodes of thepresent invention will produce a substantially uniform heating of thetissue which passes that current. To selectively target a centralportion of the tissue, in other words, to selectively heat a targetportion of the tissue separated from electrodes 12, 14, the electrodesurfaces are cooled. This cooling maintains a cooled tissue region 28adjacent each electrode below a maximum safe tissue temperature,typically being below about 45° C. Even though heat generationthroughout the gap between the electrodes is uniform, the temperatureprofile of the tissue between the electrodes can be controlled byremoving heat through the electrode surfaces during heating.

Generally, sufficient heating can be provided by a current of betweenabout 0.2 and 2.0 amps, ideally about 1.0 amp, and a maximum voltage ofbetween about 30 and 100 volts rms, ideally being about 60 volts rms.The electrodes will often have a surface area of between about 5.0 and200 cm², and the current density in the target tissue will often bebetween about 1 mA/cm² and 10 mA/cm². This will provide a maximum powerin the range from about 10 W to about 100 W, often being about 20 watts.Using such low power settings, if either electrode is lifted away fromthe engaged tissue, there will be no arcing. Instead, the current willsimply stop. This highlights the difference between the electricaltissue heating of the present invention and known electrocauterytechniques.

The ideal geometry to provide a true one-dimensional temperaturedistribution would include large parallel plate electrodes havingrelatively minimal spacing therebetween. As tissues which are easilyaccessible for such structures are fairly limited, the present inventioncan also make use of electrode geometries which vary somewhat from thisideal, particularly through the use of array electrodes. In fact, theuse of a single array electrode, in combination with a much larger,uncooled electrode pad may heat tissues disposed near the array, as willbe described hereinbelow. Nonetheless, uniform heating is generallyenhanced by providing electrode structures having tissue engagingsurfaces which are as flat and/or as parallel as practical. Preferably,the parallel electrode surfaces will be separated by between about 1/3and 1.0 times the width of the electrode surfaces (or of the smallersurface, if they are different).

The use of an array electrode having multiple electrode segments can beunderstood with reference to FIGS. 2A-2D. FIG. 2A schematicallyillustrates the shape of a target zone which is heated by selectivelyenergizing only electrode segments 12c and 14c of cooled electrodes 12and 14. Once again, it should be understood that the temperature oftarget zone 32 (here illustrated schematically with isotemperaturecontour lines 30) is the result of uniform heating between the energizedelectrode segments, in combination with cooling of tissue T by theelectrode surfaces. To expand the heated area laterally between theelectrodes, electrode segments 12a, 12b, 12c . . . , and 14a, 14b, 14c .. . , can be energized, thereby heating an entire target zone 32extending throughout tissue T between the electrodes.

The use of array electrodes provides still further flexibility regardingthe selective targeting of tissues between electrodes 12 and 14. Asillustrated in FIG. 2C, selectively energizing a relatively largeeffective electrode surface by driving electrodes segments 12a, 12b,12c, 12d, and 12e results in a low current flux which is widelydisbursed throughout the tissue T engaged by electrode 12. By drivingthis same current through a relatively small effective electrode surfaceusing only a single electrode surface segment 14c produces an offsettarget zone 34 which is much closer to electrode 14 than to electrode12.

To compensate for electrode structures which are not exactly parallel,varying amounts of electrical current can be provided to the electrodesegments. For example, a fairly uniform target zone 32 may be heatedbetween angled electrodes by driving more current through relativelywidely spaced electrode segments 12a, 14a, and driving less currentthrough more tightly spaced electrode segments 12e, 14e, as illustratedin FIG. 2D. It should be understood that these selective targetingmechanisms may be combined to target fascia and other tissues which arenear one slanted electrode, or to selectively target only a portion ofthe tissues disposed between relatively large electrode arrays.

An exemplary structure for segmented, cooled electrode 12 isschematically illustrated in FIG. 2F. Electrode 12 here comprises threeelectrode surface segments 12a, 12b, and 12c separated by insulatingspaces 21. A plastic housing 23 defines a flow path between a coolinginflow port 25 and a cooling outflow port 27, while heat transferbetween the cooling fluid and the electrode surface is enhanced by athermally conductive front plate 29. Front plate 29 generally comprisesa thermally conductive metal such as aluminum. Electrode surfacesegments 12a, 12b, and 12c may comprise surfaces of separated segments31 of aluminum foil. Segments 31 may be electrically isolated by a mylarinsulation sheet 33 disposed between the segments and front plate 29.

The array electrode structures of the present invention will generallyinclude a series of conductive surface segments which are aligned todefine a substantially flat electrode surface. The electrode surfacesegments are separated by an electrically insulating material, with theinsulation being much smaller in surface area than the conductivesegments. Typically, there will be between 1.0 and 8.0 electrodesegments, which are separated by a distance of between about 0.25 mm and1.0 mm.

It should also be understood that while the electrode arrays of thepresent invention are generally herein described with reference to alinear array geometry, the present invention also encompasses electrodeswhich are segmented into two-dimensional arrays. Where opposed sides ofthe tissue are accessible for relatively large array structures, such asalong the exposed skin, or near the major cavities and orifices of thebody, the electrode surfaces will preferably be separated by a gap whichis less than a width (and length) of the electrodes.

In some embodiments, one electrode structure may be disposed within alarge body cavity such as the rectum or vagina, while the other isplaced in an adjacent cavity, or on the skin so that the region to betreated is between the electrode surfaces. In other embodiments, one orboth electrodes may be inserted and positioned laparoscopically. It willoften be desirable to clamp the tissue tightly between the electrodes tominimize the gap therebetween, and to promote efficient coupling of theelectrode to the tissue.

As can be understood with reference to FIGS. 3-3E, the tissue willpreferably be cooled before and after energizing of the electrodes. FIG.3 illustrates three distinct regions of tissue T disposed betweenelectrodes 12 and 14. Target zone 32 will typically comprise fascia orsome other collagenated tissue, while the surfaces of the electrodesengage an intermediate tissue 36 disposed on either side of the fascia.

It will generally be desirable to maintain the temperature ofintermediate tissue 36 below a maximum safe tissue temperature toprevent injury to this intermediate tissue, the maximum safe tissuetemperature typically being about 45° C. To effect shrinkage of fascia,target zone 32 will typically be heated to a temperature above about 60°C.

There will often be a region of stunned tissue 38 disposed between thesafely cooled intermediate tissue 36 and the target zone 32. Thisstunned tissue will typically be heated in the range from about 45° C.to about 60° C., and may therefore undergo some limited injury duringthe treatment process. As a result, it is generally desirable tominimize the time this tissue is at an elevated temperature, as well asthe amount of stunned tissue.

As illustrated in FIG. 3A, prior to application of cooling or heatingenergy, the temperature profile of tissue T along an axis X betweenelectrodes 12 and 14 is substantially uniform at body temperature. Thetissue will preferably be pre-cooled by the surfaces of electrodes 12,14, generally using an electrode surface temperature of at or above 0°C. Pre-cooling will substantially decrease the temperature ofintermediate tissues 36, and will preferably at least partially decreasethe temperature of stunned tissue 38. At least a portion of the targetzone remains at or near the initial body temperature, as illustrated inFIG. 3B. Pre-cooling time will often depend on electrode separation andtissue heat diffusity.

Once the tissue has been pre-cooled, the RF current is directed throughthe tissue between the electrodes to heat the tissue. A temperaturesensor can be placed at the center of target zone 3z to help determinewhen the pre-cooling has been applied for the proper time to initiate RFheating. The current flux applies a fairly uniform heating throughoutthe tissue between the electrodes, and the electrode surfaces are oftencooled throughout the heating process. As target zone 32 has the highesttemperature upon initiation of the heating cycle, and as the target zoneis farthest from the cooled electrodes, a relatively small amount ofheat flows from the target zone into the electrodes, and the target zoneis heated to a significantly higher temperature than intermediate tissue36.

Heat is applied until the target zone is at or above a treatmenttemperature, typically resulting in a temperature distribution such asthat illustrated in FIG. 3C. To minimize collateral damage to theadjacent tissues 36 and stunned tissue 38, the cooling system continuesto circulate cold fluid through the electrode, and to remove heat fromthe tissue, after the heating radiofrequency energy is halted. Whensubstantially the entire tissue is below the maximum safe tissuetemperature, cooling can be halted, and the tissue can be allowed toreturn to standard body temperature, as illustrated in FIG. 3E.

The pelvic support tissues which generally maintain the position of theurinary bladder B are illustrated in FIG. 4. Of particular importancefor the method of the present invention, endopelvic fascia EF defines ahammock-like structure which extends between the arcus tendineus fasciapelvis ATFP. These latter structures extend between the anterior andposterior portions of the pelvic bone, so that the endopelvic fascia EFlargely defines the pelvic floor.

In women with urinary stress incontinence due to bladder neckhypermobility, the bladder has typically dropped between about 1.0 cmand 1.5 cm (or more) below its nominal position. This condition istypically due to weakening of the pelvic support structures, includingthe endopelvic fascia, the arcus tendineus fascia pelvis, and thesurrounding ligaments and muscles, often as the result of bearingchildren.

When a woman with urinary stress incontinence sneezes, coughs, laughs,or exercises, the abdominal pressure often increases momentarily. Suchpressure pulses force the bladder to descend still further, shorteningthe urethra UR and momentarily opening the urinary sphincter.

As can be most clearly understood with reference to FIGS. 4A-4C, thepresent invention generally provides a therapy which applies gentleheating to shrink the length of the support tissues and return bladder Bto its nominal position. Advantageously, the bladder is still supportedby the fascia, muscles, ligaments, and tendons of the body. Using gentleresistive heating between bipolar electrodes, the endopelvic fascia EFand arcus tendineus fascia pelvis ATFP are controllably contracted toshrink them and re-elevate the bladder toward its original position.

Referring now to FIG. 4A, bladder B can be seen to have dropped from itsnominal position (shown in phantom by outline 36). While endopelvicfascia EF still supports bladder B to maintain continence when thepatient is at rest, a momentary pressure pulse P opens the bladder neckN, resulting in a release through urethra UR.

A known treatment for urinary stress incontinence relies on sutures S tohold bladder neck N closed so as to prevent inadvertent voiding, as seenin FIG. 4B. Sutures S may be attached to bone anchors affixed to thepubic bone, ligaments higher in the pelvic region, or the like. In anycase, loose sutures provide insufficient support of the bladder neck Nand fail to overcome urinary stress incontinence, while overtighteningof sutures S may make normal urination difficult and/or impossible.

As shown in FIG. 4C, by selectively contracting the natural pelvicsupport tissues, bladder B can be elevated from its lowered position(shown by lowered outline 38). A pressure pulse P is resisted in part byendopelvic fascia EF, which supports the lower portion of the bladderand helps maintain the bladder neck in a closed configuration. In fact,fine tuning of the support provided by the endopelvic fascia is possiblethrough selective contraction of the anterior portion of the endopelvicfascia to close the bladder neck and raise bladder B upward.Alternatively, lateral repositioning of bladder B to a more forwardposition may be affected by selectively contracting the dorsal portionof endopelvic fascia EF. Hence, the therapy of the present invention maybe tailored to the particular elongation exhibited by a patient's pelvicsupport tissues.

As is more fully explained in co-pending U.S. patent application Ser.No. 08/910,370 (Attorney Docket No. 17761-000120), previouslyincorporated by reference, a wide variety of alternative conditions mayalso be treated using the methods of the present invention. Inparticular, selective shrinkage of fascia may effectively treatcystocele, hiatal, and inguinal hernias, and may even be used incosmetic procedures such as abdominoplasty (through selectivelyshrinking of the abdominal wall).

A system for selectively shrinking the endopelvic fascia is illustratedin FIG. 5. System 40 includes a vaginal probe 42 and a bladder probe 44.Vaginal probe 42 has a proximal end 46 and a distal end 48. Electrode 12(including segments 12a, 12b, 12c, and 12d) is mounted near the distalend of the probe. Vaginal probe 42 will typically have a diameter ofbetween about 2 and 4 cm, and will often have a shaft length of betweenabout 6 and 12 cm. An electrical coupling 50 is couplable to an RF powersupply, and optionally to an external control processor. Alternatively,a controller may be integrated into the probe itself. A fluid coupling52 provides attachment to a cooling fluid system. Cooling fluid may berecycled through the probe, so that more than one fluid couplers may beprovided.

The segments of electrode 12 are quite close to each other, andpreferably define a substantially flat electrode surface 54. The coolingfluid flows immediately below this surface, the surface materialpreferably being both thermally and electrically conductive. Ideally,surface 54 is as large as the tissue region to be treated, and athermocouple or other temperature sensor may be mounted adjacent thesurface for engaging the tissue surface and measuring the temperature ofthe engaged tissue.

Urethral probe 44 includes a balloon 56 supporting a deployableelectrode surface. This allows the use of a larger electrode surfacethan could normally be inserted through the urethra, by expanding theballoon structure within the bladder as illustrated in FIG. 6.Alternatively, a narrower cylindrical electrode might be used whichengages the surrounding urethra, the urethral electrode optionally beingseparated into more than one segment along the length and/or around thecircumference of the probe shaft. Radiofrequency current will divertfrom such a tightly curved surface and heat the nearby tissue. Theelectrode can again be chilled to protect the urethral lining fromthermal damage.

As illustrated in FIG. 6, the endopelvic fascia will preferably bedisposed between the electrodes of the urethral probe 44 and vaginalprobe 42. Balloon 56 of urethral probe 44 is here illustrated in itsexpanded configuration, thereby maximizing a surface area of electrode14, and also minimizing its curvature. Preferably, cooled fluidrecirculating through balloon 56 will cool electrode 14, so that cooledelectrodes 12, 14 will selectively heat the endopelvic fascia EF withoutdamaging the delicate vaginal mucosa VM or the bladder wall.

Urethral probe 44 and vaginal probe 42 may optionally be coupleable toeach other to facilitate aligning the probes on either side of thetarget tissue, either mechanically or by some remote sensing system. Forexample, one of the probes may include an ultrasound transducer, therebyfacilitating alignment of the electrode surfaces and identification ofthe target tissue. Alternatively, the proximal ends of the probes mayattach together to align the electrodes and/or clamp the target tissuebetween the probes.

Referring now to FIG. 7, a mesh electrode 58 may be unfurled within thebladder in place of urethral probe 44. Mesh electrode 58 preferablycomprises a highly flexible conductive element, optionally being formedof a shape memory alloy such as Nitinol™. The bladder may be filled withdistilled water during the therapy, so that little or no RF currentwould flow into the bladder wall beyond the contact region between theelectrode and the bladder.

FIGS. 8A and 8B illustrate an optional deployable electrode supportstructure for use with vaginal probe 42. Electrode 12 can be collapsedinto a narrow configuration for insertion and positioning within thevaginal cavity, as illustrated in FIG. 8A. Once electrode 12 ispositioned adjacent to the target tissue, electrode 12 can be expandedby inflating lateral balloon 60 so that the deployed electrode assumes asubstantially planar configuration. A cooling fluid may be recirculatedthrough lateral balloon 60 to cool the electrode 12, and a thermallyinsulating layer 62 can help to minimize heat transfer from the adjacenttissues.

Referring now to FIG. 9, the tissue shrinking system of the presentinvention may also include an ultrasonic transducer 64 for positioningone or both electrodes relative to fascia F. Transducer 64 willpreferably include a plastic transducer material such as PVDF₂(polyvinyladine fluoride) or PZT-5A (lead zirconate titanate).Transducer 64 may be incorporated into the probes of the presentinvention, thereby allowing the relative positions and angle between theelectrode surfaces to be measured directly. Alternatively, transducer 64may be positioned adjacent to fascia F, and a mark may be drawn upon theexposed skin (or other tissue surface) adjacent the fascia forsubsequent positioning of a probe.

Transducer 64 optionally includes a needle guide 66 for insertion of abiopsy needle 68 through the view of the transducer and into the fascia.A thermocouple or other temperature sensing element may then be deployedusing the biopsy needle.

Referring now to FIG. 10, an alternative tissue shrinking system 70includes an electrode 12 mounted on a speculum 72. Speculum 72 may beused to manually position electrode 12 within the vagina (or anotherbody orifice), while an external applicator 74 is positioned against theskin to clamp the target tissue between electrode 14 and electrode 12.The speculum and external applicator 74 may be manually manipulated toclamp the target tissue between these structures, while electrical leads76 and cooling fluid conduits 78 couple the probe and applicator to theremaining system components.

As described above regarding FIG. 2C, the use of bipolar electrodes ofdiffering sizes allows the selective targeting of tissues. Specifically,heating will be concentrated near the smaller electrode surface. Byusing one electrode surface which is much larger than the other, thecurrent density adjacent the large electrode will remain so low thatlittle tissue heating is produced at that site, so that the very largeelectrode surface need not be cooled. FIG. 11 schematically illustratesa single probe heating system 80 which takes advantage of this mechanismto selectively heat fascia near a single probe.

In single probe system 80, offset target zone 34 is heated by RF energyselectively directed through the segments of electrode 12. The vaginalmucosa VM disposed between vaginal probe 42 and endopelvic fascia EF isprotected by cooling the surface of electrode 12, as described above.Bladder B (and the other tissues opposite endopelvic fascia EF relativeto vaginal probe 42) are heated significantly less than endopelvicfascia EF due to the divergence of the current as it travels away fromelectrode 12 and towards electrode pad 82, which may optionally bedisposed on the abdomen, back, or thigh. Optionally, cooling water maybe circulated through bladder B to further protect these tissues.Multiplexer 20 selectively energizes the electrode segments fordiffering amounts of time and/or with differing power to help tailor thetemperature profile of offset target zone 34 about endopelvic fascia EFfor selective uniform heating with minimal collateral damage. Varioustreatment regimes with alternating heating and cooling cycles can helpto focus the heat therapy on the desired tissues.

Referring now to FIG. 12, a cooled bipolar probe 84 includes many of thestructures and features described above, but here includes a series ofbipolar electrodes 86. Bipolar electrodes 86 will preferably be cooled,and cooling surfaces may also be disposed between the separatedelectrodes. As more fully described in co-pending application Ser. No.08/910,370 (Attorney Docket No. 17761-000120), bipolar electrodes 86 mayoptionally be formed as parallel cylindrical structures separated by apredetermined spacing to help direct a bipolar current flux 88 throughtissue which lies within a particular treatment distance of probe 84.

The depth of penetration of the bipolar energy is controlled by thespacing and size of the electrode structures. The tissues distant fromthe cooled electrodes will be heated to a lesser extent than the tissuesdirectly engaged by the electrodes, but will also be cooled to a lesserextent by the cooled electrodes and other cooling surfaces of bipolarprobe 84. The tissues close to the electrodes will be heated to agreater extent, and will also be cooled more effectively. Therefore, acontrolled regimen of timed precooling and then heating is used toselectively raise the temperature of endopelvic fascia EF (or any othertarget tissue), while the vaginal mucosa adjacent probe 84 is protectedby the cooled probe. Tissues at depths greater than the endopelvicfascia will generally be protected by the dissipation of bipolar current88.

Since radiofrequency heating generally relies on conduction ofelectricity through the tissue, one additional mechanism for protectingthe tissues at depths greater than the target area would be to inject aninsulating fluid 90 into the space surrounding the vaginal wall on thefar side of endopelvic fascia EF. Insulating fluid 90 may optionallycomprise a gas such as CO₂, or may alternatively comprise a liquid suchas isotonic Dextran™ in water. Insulating fluid 90 will electricallyinsulate the adjacent organs and prevent heating of tissues that mightotherwise be in contact with the vaginal fascial outer lining.Insulating fluid 90 is here injected using a small needle incorporatedinto bipolar probe 84, the needle preferably being 22 ga or smaller.

Referring now to FIG. 13, microwave probe 94 includes microwave antennas96 which direct microwave heating energy 98 through the vaginal mucosaVM and onto endopelvic fascia EF. Microwave probe 94 will againtypically include a cooled probe surface to minimize damage to vaginalmucosa VM. The microwave may optionally be produced by a phased arraymicrowave antenna to decrease heating next to the cold probe relative tothe heating of endopelvic fascia EF, or a more conventional microwaveantenna may be used.

Microwave power having a frequency of about 2250 MHz is most often usedfor heating. However, the use of extremely high frequency microwaveswould permit constructive interference at the intersection of microwaveenergy streams by control of the microwave frequency, phase, andelectrode spacing. Such constructive interference of microwaves may beused to enhance the heating of the target tissue relative to the heatproduced in the intermediate tissue between microwave probe 94 andendopelvic fascia EF (in this example). Injection of an electricallyinsulating fluid, such as Dextran™, may be used to absorb microwaveenergy and protect tissues beyond the target zone. In some embodiments,injection of a liquid contrast medium might be used to enhancevisualization of the treatment region, increasing the visibility andclarity of the vagina V, bladder B, the other adjacent organs, and thespaces therebetween. Such a contrast medium will typically be highlyvisible under ultrasonic or fluoroscopic imaging modalities.

An alternative form of energy which may be used in a probe schematicallysimilar to that illustrated in FIG. 13 is ultrasonic heating. A cooledultrasonic probe could be used to provide heating of the endopelvicfascia adjacent the vagina, preferably while protecting the adjacenttissues using a material which reflects ultrasound. Suitable protectionmaterials include CO₂ or a liquid/foam emulsion material. High intensityultrasound is able to heat tissues at a distance from the probe, and maybe focused to apply the most intense heating at a particular treatmentsite. Concentration of ultrasound energy deep in the body may avoidheating of tissues at the entry site of the focused ultrasound beam,although gas pockets and bony structures may absorb and/or reflect thefocused ultrasound energy, so that tissues may be damaged by bothlocalized heating and cavitation. Once again, the surface of anultrasound probe will typically be cooled to protect the tissues whichare directly engaged by the probe.

A cross-section of a grasping bipolar probe 100 is illustrated in FIG.14. Grasping probe 100 grips and folds an anterior portion of thevaginal wall, including both the vaginal mucosa VM and endopelvic fasciaEF, as shown. It should be understood that the targeted fascia may beseparated from the probe by muscle, vasculature, and the like, as wellas by vaginal mucosa VMO. Endopelvic fascia EF is typically about 1 mmthick, while the grasped, folded vaginal wall will typically be betweenabout 10 mm to 14 mm thick. The folded endopelvic fascia EF may thus beheated and contracted between cooled bipolar electrodes 102, asdescribed above. Depending on the length of the fold, cooled bipolarelectrodes 102 may optionally be formed as wide elongate plates.Grasping may be accomplished mechanically or by applying a vacuum todraw the vaginal wall into a cavity 104 of grasping probe 100. Bydrawing the endopelvic fascia into close proximity of both electrodes, afiner focusing of the heating may be accomplished, thereby minimizingthe damage to adjacent tissues. Additionally, grasping probe 100 maydraw the tissue inward to relieve any tension in the fascia, therebyenhance the shrinkage. As described above regarding FIG. 12, CO₂ or someother insulating medium may be used for additional protection ofadjacent tissues and organs.

A kit 110 includes vaginal probe 42 and instructions 112 for use of theprobe to shrink tissues, the probe and instructions disposed inpackaging 114. The instructions may set forth the method steps for usingprobe 42 described hereinabove for selectively shrinking pelvic supporttissues as a therapy for urinary incontinence, or may alternativelyrecite any of the other described methods. Additional elements forsystem 10 (see FIG. 1) may also be included in kit 110, or may bepackaged separately.

Instructions 112 will often comprise printed material, and may be foundin whole or in part on packaging 114. Alternatively, instructions 112may be in the form of a recording disk or other computer-readable data,a video tape, a sound recording, or the like.

The present invention further encompasses methods for teaching theabove-described methods by demonstrating the methods of the presentinvention on patients, animals, physical or computer models, and thelike.

While the exemplary embodiments have been described in some detail, byway of example and for clarity of understanding, a variety ofmodifications, adaptations, and changes will be obvious to those whoskill in the art. For example, substantially coaxial cylindricalelectrode surfaces may clamp tubular tissues (such as the cervix)between cooled parallel surfaces for treatment and/or shrinkage.Therefore, the scope of the present invention is limited solely by theappended claims.

What is claimed is:
 1. A system for therapeutically heating a targetzone within a tissue, the system comprising:a first electrode having afirst electrode surface which is engagable against the tissue; a secondelectrode having a second electrode surface which can be alignedsubstantially parallel to the first electrode surface with the tissuetherebetween so that an electrical current flux between the electrodescan substantially evenly heat the target zone, the first and secondelectrode surfaces substantially flat to distribute the current fluxthroughout the tissue between the electrodes; a cooling system coupledto at least one of the electrodes for cooling at least one of theelectrode surfaces; and a positioning system coupled to at least one ofthe first electrode and the second electrode, the positioning systemcapable of aligning the electrode surfaces along substantially opposedsurfaces of the tissue.
 2. A device as claimed in claim 1, wherein eachelectrode surface comprises a plurality of electrode surface segments,and further comprising a control system coupled to each electrodesurface segment, the control system capable of selectively energizingthe electrode surface segments to vary the current flux within thetarget zone.
 3. A method for therapeutically heating a target zone of apatient body, the target zone disposed within a tissue between first andsecond tissue surfaces, the method comprising:engaging a first electrodesurface against the first tissue surface; aligning a second electrodesurface substantially parallel with the first electrode surface andagainst the second tissue surface with a positioning system coupled toat least one of the first electrode surface and the second electrodesurface; applying an electrical potential between the first and secondelectrodes, the electrical potential producing an electrical currentflux between the electrodes which heats the target zone, the electrodesurfaces being sufficiently large and sufficiently flat to distributethe current flux throughout the target zone; and cooling at least one ofthe first and second tissue surfaces with the engaged electrode.
 4. Amethod as claimed in claim 3, further comprising monitoring atemperature of the tissue and varying the current flux in response tothe temperature.
 5. A method as claimed in claim 3, further comprisingdirecting the current flux from the at least one cooled electrode intothe tissue so as to evenly heat the target zone.
 6. A method as claimedin claim 5, wherein the flux directing step comprises selectivelyvarying the electrical potential across at least one of the electrodesurfaces, the at least one electrode surface comprising a plurality ofelectrode surface segments.
 7. A method as claimed in claim 6, whereinthe cooling step comprises cooling the first and second electrodesurfaces.
 8. A method as claimed in claim 7, further comprising clampingthe tissue between the electrode surfaces so that a gap between theelectrode surfaces is less than a width and a length of each electrodesurface.
 9. A method as claimed in claim 5, wherein the cooling stepcomprises maintaining the tissue adjacent the first tissue surface belowa safe tissue temperature, the target zone being separated from thefirst tissue surface by a cooled tissue depth.
 10. A method as claimedin claim 9, wherein the energy directing step further comprisesselectively energizing a plurality of electrode surface segments of thefirst electrode so as to vary an effective size of the first electrodeand change the cooled tissue depth.